Lipiodol produced and marketed by the French company Guerbet is a fatty acid ethyl ester of iodized poppyseed oil that is injected into the body as a radio-opaque contrast agent for outlining and visualizing internal anatomical structures in radiological examinations. For example, Lipiodol has been used as a contrast agent in lymphangiography, hysterosalpingography, and for diagnosing gastric and hepatic lesions.
Due to increased incidence of diseases such as cancer and stroke in recent years, there is an increasing demand for radio-opaque contrast agent such as Lipiodol to be used in radiological examinations for diagnostic purpose. However, Lipiodol is of relatively high cost. Therefore, it is desirable for those skilled in the art to develop an iodinated fatty acid ethyl ester which may be synthesized from inexpensive and easily available edible oil to be used as a substitute for Lipiodol.
CN103045373B discloses a method for preparing iodinated vegetable oil ethyl ester in which vegetable oil and hydrogen iodide gas are subjected to an addition reaction to generate iodinated vegetable oil. The addition reaction is implemented at a temperature of 25° C. for a period ranging from 16 hours to 96 hours.
CN101676255A discloses a synthetic method for preparing iodinated vegetable fatty acid and ester thereof. In the synthetic method, vegetable fatty acid prepared from vegetable oil via saponification and acidification reactions is subjected to an iodination reaction with hydroiodic acid to obtain iodinated vegetable fatty acid. The iodination reaction is implemented at a temperature ranging from 0° C. to 50° C. for a period ranging from 1 hour to 96 hours.
Both of the methods disclosed in the aforesaid prior art have a relatively slow reaction rate, and are thus time-consuming.